Extracting causal impulse responses from baseband band-limited S-parameters of passive photonic integrated circuits for time-domain simulations.

The dispersive characteristics and wavelength-dependent behaviors of passive photonic integrated circuits (PICs) can be well described by S-parameters. However, circuit-level simulations of PICs that commonly consist of both passive and active components have to be conducted in the time domain. Thus, S-parameters need to be converted into a time-domain representation without losing accuracy and violating physical properties (e.g., causality). To address this issue, this paper proposes an approach for extracting causal impulse responses of passive PICs by extrapolating their baseband band-limited S-parameters. The method is efficient and robust for a wide range of passive PICs.

Characterization and transformation of TtMYB1 transcription factor from Tritipyrum to improve salt tolerance in wheat.

BACKGROUND: Common wheat (Triticum aestivum L.) is a worldwide cereal crop, which is an integral part of the diets of many countries. In addition, the MYB gene of wheat plays a role in the response to salt stress. RESULTS: "Y1805" is a Tritipyrum variety that is relatively tolerant to salt. We used transcriptome analysis to show that the "Y1805" MYB gene was both highly expressed and sensitive to salt stress. Compared with control roots, the level of MYB expression during salt stress was higher, which rapidly decreased to control levels during the recovery process. MYB gene relative expression showed the highest levels in "Y1805" roots during salt stress, with the stems and then leaves being the next highest stressed tissues. The novel MYB gene (TtMYB1) was successfully cloned from "Y1805". It showed a coding sequence length of 783 bp with 95.79% homology with Tel2E01G633100 from Thinopyrum elongatum. TtMYB1 and MYB from Th. elongatum were clustered in the same branch using phylogenetic analysis, which indicated high similarities. The TtMYB1 gene is located in the nucleus. The coleoptile method was employed when a TtMYB1 overexpression vector was used during transformation into "1718" (common wheat). Under high salt stress, TtMYB1 leaves of overexpression lines had decreased wilting, when compared with wild-type (WT) plants. During normal conditions, salt stress, and recovery, the lengths of the roots and the heights of seedlings from the overexpression lines were found to be significantly greater than roots and seedlings of WT plants. In addition, during high salt stress, the overexpression lines showed that proline and soluble sugar levels were higher than that of WT plants, but with lower malondialdehyde levels. Forty-three proteins that interacted with TtMYB1 were identified using the yeast two-hybrid assay. Protein-protein interaction analyses indicated that most were SANT domain-containing and Wd repeat region domain-containing proteins. Among these proteins, ribosomal proteins were the main node. Abiotic stress-related terms (such as "carbonate dehydratase activity", "protein targeting peroxisomes", and "glutathione peroxidase activity") were enriched in GO analysis. In KEGG analysis, "carbohydrate metabolism", "environmental information processing", "genetic information processing", "signaling and cell precursors", and "energy metabolism" pathways were enriched. CONCLUSION: The TtMYB1 gene might enhance salt tolerance by increasing proline and soluble sugar content and antioxidase activity in transgenic wheat. It therefore has the potential to enhance high salt tolerance in plants.

Directed Concentrating of Micro-/Nanoparticles via Near-Infrared Laser Generated Plasmonic Microbubbles.

Directed concentrating of micro- and nanoparticles via laser-generated plasmonic microbubbles in a liquid environment is an emerging technology. For effective heating, visible light has been primarily employed in existing demonstrations. In this paper, we demonstrate a new plasmonic platform based on nanoporous gold disk (NPGD) array. Thanks to the highly tunable localized surface plasmon resonance of the NPGD array, microbubbles of controlled size can be generated by near-infrared (NIR) light. Using NIR light provides several key advantages over visible light in less interference with standard microscopy and fluorescence imaging, preventing fluorescence photobleaching, less susceptible to absorption and scattering in turbid biological media, and much reduced photochemistry, phototoxicity, and so forth. The large surface-to-volume ratio of NPGD further facilitates the heat transfer from these gold nanoheaters to the surroundings. While the microbubble is formed, the surrounding liquid circulates and direct microparticles randomly dispersed in the liquid to the bottom NPGD surface, which can be made to yield a unique collection of 3D hollow dome microstructures with bubbles larger than 5 µm. Such capability can also be employed in concentrating suspended colloidal nanoparticles at desirable sites and with the preferred configuration enhancing the sensor performance. Specifically, the interaction among concentrated nanoparticles and their interactions with the underlying substrate have been investigated for the first time. These collections have been characterized using optical microscopy, scanning electron microscopy, hyperspectral localized surface plasmon resonance imaging, and hyperspectral Raman imaging. In addition to various micro- and nanoparticles, the plasmonic microbubbles are also shown to collect biological cells and extracellular nanovesicles such as exosomes. By using a spatial light modulator to project the laser in arbitrary patterns, parallel concentrating can be achieved to fabricate an array of clusters.

Hydrogen sulfide ameliorates disorders in the parafacial respiratory group region of neonatal rats caused by prenatal cigarette smoke exposure via an antioxidative effect.

We previously found that hydrogen sulfide (H2S) ameliorated the dysfunction of central chemoreception caused by prenatal cigarette smoke exposure (CSE). In the present study, we further explored whether the parafacial respiratory group (pFRG) is involved in the protection of central chemoreception by H2S against prenatal CSE-induced injury. We found that NaHS, a donor of H2S, restored the expression of Phox2b, which was downregulated by prenatal CSE, in the pFRG region of neonatal rats. NaHS also relieved the prenatal CSE-induced excitatory synapse disturbance in the pFRG region of neonatal rats. Additionally, NaHS prevented the increase in the malondialdehyde level and suppression of antioxidase activity in the pFRG region of neonatal rats induced by prenatal CSE. Furthermore, NaHS prevented the downregulation of the expression of antioxidases and Nrf2 in the pFRG region of neonatal rats with prenatal CSE. These results suggest that H2S can protect the pFRG of neonatal rats against prenatal CSE-induced injury via an antioxidative effect.

Symmetry Breaking-Induced Plasmonic Mode Splitting in Coupled Gold-Silver Alloy Nanodisk Array for Ultrasensitive RGB Colorimetric Biosensing.

We report the first observation of symmetry breaking-induced mode splitting in coupled gold-silver alloy nanodisk array (ANA). According to the plasmonic hybridization picture, the original localized surface plasmon resonance (LSPR) of individual nanodisk is split into a pair of high and low energy modes when placed in between a superstrate and a substrate. Although well studied in single silver nanoparticles, the high energy mode has been largely suppressed in gold nanoparticles, which nevertheless are more chemically robust and have superior environmental stability. Herein, we show that the high energy mode can be partially restored and precisely engineered to ∼540 nm for silver-rich alloy nanodisk which has excellent environmental stability. However, peak broadening and red-shifting occur due to plasmonic dephasing when the nanodisk diameter increases. We next demonstrate that a far-field coupled ANA fabricated by low-cost nanosphere lithography can fully restore the high energy mode with electric field concentration extended into the superstrate, thereby imparting greater sensitivity to local refractive index changes. The high energy mode at 540 nm is of key importance for color change detection using low-cost RGB cameras/human vision and broadband light sources (e.g., the sun). The index sensitivity of ANA is the highest among existing plasmonic arrays (particles or holes) within a similar resonance wavelength region. We demonstrate colorimetric detection of sub-nanomolar and sub-monolayer biotin-streptavidin surface binding with a smartphone camera and a white light lamp. The high performance yet low-cost fabrication and detection technology could potentially result in affordable point-of-care biosensing technologies.

Purification, characterization, antioxidant and moisture-preserving activities of polysaccharides from Rosa rugosa petals.

The present study, we prepared polysaccharides from Rosa rugosa petals (RRPS) using hot-water extraction and purified the polysaccharides by chromatography to obtain RRPS-1 and RRPS-2. Preliminary structural features of RRPS were characterized by different instrumental methods, such as HPGPC, FT-IR, and GC analysis. The average molecular weights of RRPS-1 and RRPS-2 were 8.8 kDa and 443.8 kDa, respectively. Then, antioxidant and moisture-preserving activities of RRPS were determined in vitro. The analysis of antioxidant activities suggested that RRPS-2 had good potential for scavenging activity of radicals. We also found that the RRPS-2 has strong moisture-preserving activity in vitro. These results clearly indicated that RRPS-2 might have a good potential to be utilized in pharmaceutical, food and cosmetics industries.

Protective Effects of Hydrogen Sulfide Against Cigarette Smoke Exposure-Induced Placental Oxidative Damage by Alleviating Redox Imbalance via Nrf2 Pathway in Rats.

BACKGROUND/AIMS: Cigarette smoke exposure (CSE) during pregnancy is a well-recognized health hazard that causes placental damage. Hydrogen sulfide (H2S) has been reported to protect multiple organs from injury. However, the protective effects of H2S have not been tested in the placenta. This study aimed to explore the potential of H2S in protecting placenta against oxidative injury induced by CSE during pregnancy and the possible underlying mechanisms. METHODS: Pregnant SD rats were randomly divided into 4 groups: NaCl, NaHS (a donor of H2S), CSE and CSE+NaHS. Placental oxidative damage was detected by 8-hydroxy-2-deoxyguanosine (8-OHdG) stain and malondialdehyde (MDA) assay. Placental redox status was assessed by measuring reactive oxygen species (ROS), total antioxidant capacity (T-AOC) and glutathione (GSH) levels, as well as copper/zinc SOD (SOD1), manganese SOD (SOD2), catalase (CAT) and glutathione peroxidase (GPx) activities and expressions. Meanwhile, nuclear factor erythroid 2-related factor 2 (Nrf2) was analyzed by immunohistochemistry, real-time PCR and Western blot. RESULTS: We found that NaHS markedly reduced the elevated levels of 8-OHdG and MDA induced by CSE. Further, NaHS treatment effectively mitigated CSE-induced placental redox imbalance by inhibiting ROS production, restoring T-AOC level, increasing GSH/GSSG ratio, and augmenting SOD1 SOD2, CAT and GPx activities and expressions. More notably, NaHS administration also reversed the aberrant decrease of Nrf2 due to CSE in rat placentas. CONCLUSION: Our data demonstrate that H2S can protect against CSE-induced placental oxidative damage probably by alleviating redox imbalance via Nrf2 pathway.

Photothermal generation of programmable microbubble array on nanoporous gold disks.

We present a novel technique to generate microbubbles photothermally by continuous-wave laser irradiation of nanoporous gold disk (NPGD) array covered microfluidic channels. When a single laser spot is focused on the NPGDs, a microbubble can be generated with controlled size by adjusting the laser power. The dynamics of both bubble growth and shrinkage are studied. Using computer-generated holography on a spatial light modulator (SLM), simultaneous generation of multiple microbubbles at arbitrary locations with independent control is demonstrated. A potential application of flow manipulation is demonstrated using a microfluidic X-shaped junction. The advantages of this technique are flexible bubble generation locations, long bubble lifetimes, no need for light-adsorbing dyes, high controllability over bubble size, and relatively lower power consumption.

Application of a double-colour upconversion nanofluorescent probe for targeted imaging of mantle cell lymphoma.

Upconversion nanoparticles are a new type of fluorescent marker in biomedical imaging that can convert a longer wavelength (such as near-infrared fluorescence) into a shorter wavelength (such as visible light). Mantle cell lymphoma, which is derived from B-cell lymphoma, is a subtype of non-Hodgkin's lymphoma, and the immune phenotype is a mature B-cell phenotype (CD20+, CD5+). To develop the use of nanomaterials as specific markers for the medical imaging of mantle cell lymphoma, we modified the surface of UCNPs by oxidation so that the CD20 or CD5 antibody could covalently attach to the upconversion nanoparticles to form antibody-UCNP conjugates. These antibody-UCNP conjugates were used as fluorescent probes to detect the CD20 or CD5 antigen. Due to the excessive expression of these antigens on the surface of MCL cells and successful strong connection between the antibody and UCNPs, the latter could specifically combine with mantle cell lymphoma cells. Upon near-infrared excitation at 980 nm, cells labelled with UCNPs emitted bright upconversion fluorescence.

Plasmonic nanoparticle-based expansion microscopy with surface-enhanced Raman and dark-field spectroscopic imaging.

Fluorescence-based expansion microscopy (ExM) is a new technique which can yield nanoscale resolution of biological specimen on a conventional fluorescence microscope through physical sample expansion up to 20 times its original dimensions while preserving structural information. It however inherits known issues of fluorescence microscopy such as photostability and multiplexing capabilities, as well as an ExM-specific issue in signal intensity reduction due to a dilution effect after expansion. To address these issues, we propose using antigen-targeting plasmonic nanoparticle labels which can be imaged using surface-enhanced Raman scattering spectroscopy (SERS) and dark-field spectroscopy. We demonstrate that the nanoparticles enable multimodal imaging: bright-field, dark-field and SERS, with excellent photostability, contrast enhancement and brightness.

Hydrogen sulfide protects neonatal rat medulla oblongata against prenatal cigarette smoke exposure via anti-oxidative and anti-inflammatory effects.

We previously demonstrated that hydrogen sulfide (H2S) protected neonatal rat medulla oblongata from prenatal cigarette smoke exposure (CSE) via anti-apoptotic effect. The present work further investigated the involvement of anti-oxidative and anti-inflammatory effects of H2S in the protection. Pregnant Sprague-Dawley rats were randomly divided into NaCl, CSE, CSE + NaHS (a donor of H2S) and NaHS groups. All the tests were performed with corresponding neonatal rats. Nissl staining revealed that NaHS treatment ameliorated neuronal chromatolysis in the hypoglossal nucleus and nucleus ambiguus resulted from prenatal CSE. Moreover, NaHS eliminated decrease of glutathione level, increase of malondialdehyde content and inhibition of superoxide dismutase activity within neonatal rat medulla oblongata caused by prenatal CSE. NaHS also relieved the up-regulation of tumor necrosis factor-α, interleukin-1ß and interleukin-6 in the medulla oblongata of the neonatal CSE rats. These results suggest that H2S can alleviate prenatal CSE-induced injuries of neonatal rat medulla oblongata through anti-oxidative and anti-inflammatory effects.

Hydrogen sulfide alleviates placental injury induced by maternal cigarette smoke exposure during pregnancy in rats.

Maternal cigarette smoke exposure (CS) during pregnancy is a well recognized causative factor for placental injury. Hydrogen sulfide (H2S), a gaseous signal molecule, has been shown to exert a protective effect against tissue injury in many organs. This study aimed to investigate whether H2S could alleviate CS-induced placental injury in rats. Pregnant SD rats were randomly divided into 4 groups: NaCl, CS, CS + NaHS (a donor of H2S) and NaHS. On gestational day 21, placental and fetal weights were measured. Placental H2S content was assessed by methylene blue method. Placental histological changes were examined by light microscopy and transmission electron microscopy. The results showed that administration of NaHS significantly attenuated CS-induced decrease in placental and fetal weights. Moreover, NaHS injection markedly alleviated CS-induced reduction in placental H2S content. Meanwhile, NaHS treatment obviously improved CS-induced morphological changes of placental junctional and labyrinthine zones. More notably, NaHS administration in CS rats was also found to ameliorate placental ultrastructural alterations, as indicated by decrease in the thickness of placental barrier, prevention of apical microvilli loss, alleviation of endoplasmic reticulum swelling and reduction in the number of vacuoles in trophoblast cells. Taken together, these findings demonstrate that administration of NaHS can alleviate CS-induced placental injuries in rats, suggesting that H2S may have therapeutic potential for treatment of placental injury caused by CS.

Nanoporous Gold Nanocomposites as a Versatile Platform for Plasmonic Engineering and Sensing.

Plasmonic metal nanostructures have shown great potential in sensing applications. Among various materials and structures, monolithic nanoporous gold disks (NPGD) have several unique features such as three-dimensional (3D) porous network, large surface area, tunable plasmonic resonance, high-density hot-spots, and excellent architectural integrity and environmental stability. They exhibit a great potential in surface-enhanced spectroscopy, photothermal conversion, and plasmonic sensing. In this work, interactions between smaller colloidal gold nanoparticles (AuNP) and individual NPGDs are studied. Specifically, colloidal gold nanoparticles with different sizes are loaded onto NPGD substrates to form NPG hybrid nanocomposites with tunable plasmonic resonance peaks in the near-infrared spectral range. Newly formed plasmonic hot-spots due to the coupling between individual nanoparticles and NPG disk have been identified in the nanocomposites, which have been experimentally studied using extinction and surface-enhanced Raman scattering. Numerical modeling and simulations have been employed to further unravel various coupling scenarios between AuNP and NPGDs.

Hydrogen sulfide ameliorates prenatal cigarette smoke exposure-induced impairment of respiratory responses to hypercapnia in neonatal rats.

The present study was designed to investigate whether H2S could improve the respiratory responses to hypercapnia blunted by prenatal CSE in neonatal rats in vivo. Respiratory activities were recorded with head-out body plethysmography. The results showed that during baseline, respiratory frequency (FR), tidal volume (VT) and minute ventilation (VE) were similar among tested groups; frequency of spontaneous apnea (FSA), not post-sigh apnea (FPA), was significantly elevated by prenatal CSE. During hypercapnia, the increases in FR and VE were significantly reduced, but VT was not markedly different, in CSE group; both FSA and FPA were decreased, although FSA remained higher in CSE group. All the aforementioned effects induced by CSE on respiratory activities were relieved by NaHS (donor of H2S, 56µmol/kg by intraperitoneal injection). These data indicate that H2S could ameliorate the disruption of respiratory responses to hypercapnia induced by prenatal CSE in neonatal rats.

Catalytic assembly of DNA nanostructures on a nanoporous gold array as 3D architectures for label-free telomerase activity sensing.

Telomerase, an enzyme known to catalyze telomere elongation by adding TTAGGG [thymine (T), adenine (A), and guanine (G)] repeats to the end of telomeres, is vital for cell proliferation. Overexpression of telomerase has been found in most tumor cells, resulting in telomere dysfunction and uncontrolled cellular proliferation. Thus, telomerase has been considered as a potential cancer biomarker, as well as a potential target in cancer therapy. In this study, telomerase-catalyzed growth of tandem G-quadruplex (G4) assembled on a nanoporous gold array (NPGA) resulted in the formation of three-dimensional hybrid nanoarchitectures. The generated nanostructure then captured malachite green (MG) (reporter molecule) without the need of a complicated labeling process. Upon laser irradiation, the captured MG molecules produced a surface-enhanced Raman scattering (SERS) signal that was generated by an abundant amount of plasmonic hot spots in the NPGA substrates. A limit of detection (LOD) of 10-10 IU along with a linear range, which was 3 orders of magnitude, was achieved, which was equivalent to the telomerase amount extracted from 20 HeLa cells. The LOD is 2 orders of magnitude better than that of the commercial enzyme-linked immunosorbent assay (ELISA), and it approaches that of the most sensitive technique, telomeric repeat amplification protocols (TRAP), which require a laborious and equipment-intensive polymerase chain reaction (PCR). In addition, X-ray photoelectron spectroscopy (XPS) was used to chemically identify and quantify the telomerase activity on the sensitized NPGA surface. Furthermore, the sensor was applied to screen the effectiveness of anti-telomerase drugs such as zidovudine, thus demonstrating the potential use of the sensor in telomerase-based diagnosis and drug development. Moreover, the framework represents a novel paradigm of collaborative plasmonic intensification and catalytic multiplication (c-PI/CM) for label-free biosensing.

Far-field plasmonic coupling in 2-dimensional polycrystalline plasmonic arrays enables wide tunability with low-cost nanofabrication.

We report the experimental observation and numerical modeling study of far-field plasmonic coupling (FFPC) in 2-dimensional polycrystalline plasmonic arrays consisting of "single crystalline" domains of a random size and orientation. Even though polycrystalline plasmonic arrays are routine products of low-cost nanosphere lithography (NSL), their FFPC behavior has not been well understood. Herein, FFPC observed from gold nanodisk (AuND) arrays fabricated using NSL appears, qualitatively, to be in keeping with that of highly regular nanoparticle arrays, where they induced cyclic modulations on the peak position and linewidth of the localized surface plasmon resonance (LSPR). Remarkable blue shifts as large as 1000 nm with nearly doubled linewidth were observed experimentally. Numerical modeling was systematically carried out and showed quantitative agreement with the experimental results. Using the modeling approach, the influences of array randomness and particle size on FFPC have been studied independently for the first time. Finally, two potential applications have been developed for FFPC-based LSPR tuning. Firstly, when AuND arrays are fabricated on flexible substrates, a novel transduction mechanism can be established between the LSPR peak position and the substrate strain. Owing to the far-field propagating nature, FFPC-based transduction can effectively extend the strain-tuning displacement range by an order of magnitude compared with those based on near-field coupling. Secondly, we show that FFPC leads to an LSPR peak within 1 µm for nanoporous gold disk arrays, which otherwise have a single particle LSPR peak beyond 1.5 µm. Such a significant FFPC-induced blue shift is critically important for compatibility with the use of silicon-based detectors.

Direct-write patterning of nanoporous gold microstructures by in situ laser-assisted dealloying.

We report a novel patterning technique to direct-write microscale nanoporous gold (NPG) features by projecting laser patterns using a spatial light modulator (SLM) onto an Au/Ag alloy film immersed in diluted nitric acid solutions. Heat accumulation induced by the photothermal effect enables localized dealloying in such solutions, which is otherwise impotent at room temperature. Consequently, NPG micropatterns are formed at the irradiated spots while the surrounding alloy remains intact. We have studied the size of the patterned NPG microstructures with respect to laser power and irradiation time. The NPG microstructures become significantly more transparent compared to the original alloy film. The NPG microstructures also exhibit strong localized surface plasmon resonance (LSPR) which is otherwise weak in the original alloy film. Both the light transmission intensity and LSPR peak wavelength have been demonstrated to be sensitive to the local environmental refractive index as quantified by microscopy and spectroscopy.

Nanoporous Gold Disks Functionalized with Stabilized G-Quadruplex Moieties for Sensing Small Molecules.

We report label-free small molecule sensing on nanoporous gold disks functionalized with stabilized Guanine-quadruplex (G4) moieties using surface-enhanced Raman spectroscopy (SERS). By utilizing the unique G4 topological structure, target molecules can be selectively captured onto nanoporous gold (NPG) disk surfaces via π-π stacking and electrostatic attractions. Together with high-density plasmonic "hot spots" of NPG disks, the captured molecules produce a remarkable SERS signal. Our strategy represents the first example of the detection of foreign molecules conjugated to nondouble helical DNA nanostructures using SERS while providing a new technique for studying the formation and evolution of G4 moieties. The molecular specificity of G4 is known to be controlled by its unit sequence. Without losing generality, we have selected d(GGT)7GG sequence for the sensing of malachite green (MG), a known carcinogen frequently abused illegally in aquaculture. The newly developed technique achieved a lowest detectable concentration at an impressive 50 pM, two orders of magnitude lower than the European Union (EU) regulatory requirement, with high specificity against potential interferents. To demonstrate the translational potential of this technology, we achieved a lowest detectable concentration of 5.0 nM, meeting the EU regulatory requirement, using a portable probe based detection system.

Simultaneous Chemical and Refractive Index Sensing in the 1-2.5 µm Near-Infrared Wavelength Range on Nanoporous Gold Disks.

Near-infrared (NIR) absorption spectroscopy provides molecular and chemical information based on overtones and combination bands of the fundamental vibrational modes in the infrared wavelengths. However, the sensitivity of NIR absorption measurement is limited by the generally weak absorption and the relatively poor detector performance compared to other wavelength ranges. To overcome these barriers, we have developed a novel technique to simultaneously obtain chemical and refractive index sensing in 1-2.5 µm NIR wavelength range on nanoporous gold (NPG) disks, which feature high-density plasmonic hot-spots of localized electric field enhancement. For the first time, surface-enhanced near-infrared absorption (SENIRA) spectroscopy has been demonstrated for high sensitivity chemical detection. With a self-assembled monolayer (SAM) of octadecanethiol (ODT), an enhancement factor (EF) of up to ∼10(4) has been demonstrated for the first C-H combination band at 2400 nm using NPG disk with 600 nm diameter. Together with localized surface plasmon resonance (LSPR) extinction spectroscopy, simultaneous sensing of sample refractive index has been achieved for the first time. The performance of this technique has been evaluated using various hydrocarbon compounds and crude oil samples.

Impairment of Central Chemoreception in Neonatal Rats Induced by Maternal Cigarette Smoke Exposure during Pregnancy.

It has been postulated that prenatal cigarette smoke exposure (CSE) increases the risk for sudden infant death syndrome. The victims of infant death syndrome suffer from respiratory abnormalities, such as central apnea, diminished chemoreflex and alteration in respiratory pattern during sleep. However, no experimental evidence on CSE model exists to confirm whether prenatal CSE gives rise to reduction of neonatal central chemoreception in in vitro preparations in absence of peripheral sensory feedback. The aim of the present study was to test the hypothesis that maternal CSE during pregnancy depresses central chemoreception of the neonatal rats. The pregnant rats were divided into two groups, control (n = 8) and CSE (n = 8). Experiments were performed on neonatal (0-3days) rat pups. Fictive respiratory activity was monitored by recording the rhythmic discharge from the hypoglossal rootlets of the medullary slices obtained from the neonatal rats. The burst frequency (BF) and integrated amplitude (IA) of the discharge were analyzed. Their responses to acidified artificial cerebrospinal fluid (aCSF) were tested to indicate the change of the central chemosensitivity. Under condition of perfusing with standard aCSF (pH 7.4), no significant difference was detected between the two groups in either BF or IA (P>0.05). Under condition of perfusing with acidified aCSF (pH 7.0), BF was increased and IA was decreased in both groups (P<0.01). However, their change rates in the CSE group were obviously smaller than that in the control group, 66.98 ± 10.11% vs. 143.75 ± 15.41% for BF and -22.38 ± 2.51% vs. -44.90 ± 3.92% for IA (P<0.01). In conclusion, these observations, in a prenatal CSE model, provide important evidence that maternal smoking during pregnancy exerts adverse effects on central chemoreception of neonates.